毛竹叶片衰老特性及衰老相关基因的筛选和鉴定

收集野外定植3年的毛竹秆上具有明显衰老渐进特征的叶片簇,测量这些叶片的光合代谢效率(Fv/Fm)及叶绿素含量,建立毛竹不同衰老阶段叶片形态与其光合效率之间的关系.在此基础上,通过生物信息学方法(BLASTn)筛选出113个毛竹基因组中与水稻叶片衰老调控相关的同源基因,并检测这些基因在毛竹叶片发育和衰老过程中的表达趋势,鉴定一些与毛竹叶片衰老相关的标志基因.结果显示,毛竹叶片在衰老过程中其叶片的光合效率和叶绿素含量均出现显著下降;在筛选的113个基因中有86个基因在叶片中表达,其中32个基因在叶片衰老过程中没有变化,41个基因随着叶片衰老出现显著下调,13个基因出现明显上调.这些表达变化的基因与水稻中鉴定的同源基因在旗叶衰老过程中的表达模式基本一致,因此这些基因很可能在毛竹叶片衰老过程中也发挥同样的功能.

Leaf senescence characteristics and the screen and identification of leaf senescence associated genes in moso bamboo

Clusters of moso bamboo ( Phyllostachys heterocycla var. pubescens) leaves that showed obvious progressive senescence characteristics in bamboo culms and have been planted in field for 3 years were collected. Photochemical efficiency of photosystemⅡ( Fv/Fm) and chlorophyll contents were measured in these leaves so as to establish a relationship between leaf senescence degree and photosynthesis efficiency. Meanwhile, by using bioinformatics analysis ( BLASTn) , 113 genes in bamboo genome which showed homology to the leaf senescence-associated genes of rice ( Oryza sativa) were obtained, and their expression trend in leaves during development and senescence process were detected, which aimed to discover some leaf senescence associated marker genes. The re-sults showed that photochemical efficiency of photosystemⅡand the contents of chlorophyll in bamboo leaves decreased significantly during senescence. And in the detection of gene expression, 86 out of the 113 genes were expressed in bamboo leaves. Among them, expression levels of 32 genes remained the same, but expression levels of 41 genes significantly decreased during leaf senescence process, while those of 13 genes increased. The expression pattern of those differentially expressed genes in moso bamboo are very similar to their homologous genes in rice plant during flag leaf senescence process, indicating that these genes may play the same regulatory function in both rice and bamboo which are associated with leaf senescence.